Nitrogen Requirement of Prosopis velutina Seedlings

The objective of this study was to determine whether mesquite (Prosopis velutina) seedlings have a preference for the ammonia or nitrate form of nitrogen (N), and to determine the optimum rate of N to maximize growth and minimize N leaching when seedlings are grown in different substrates. Mesquite seedlings were fertigated with different ratios of NH4+: NO3- to determine effects on shoot and root growth and N-uptake efficiency. Nutrient solution containing 67% NH4+ : 33% NO3- resulted in greatest biomass after 120 days of fertigation. N leachate remained stable until 12 weeks after the onset of treatment, but increased significantly by week 16. Subsequently, mesquite seedlings were grown in sand or soilless media and were fertigated with a solution of 67 % NH4+: 33% NO3- at a rate of 25, 50, 100, or 200 mg·L-1 of N. After 60 days, plants in media produced 41% more leaves and total biomass compared to those in sand. Leaf number was greatest for plants grown at 200 mg·L-1 of N in both substrates. Root biomass of plants in media showed no response to increasing N concentrations while root biomass of seedlings in sand were similar for the three lower N concentrations and nearly doubled for the highest one. Shoot biomass of seedlings receiving 25, 50, or 100 mg·L-1 of N was similar, but more than doubled for plants fertigated with 200 mg·L-1 of N. N leachate losses were highest from seedlings growing in sand and receiving the two higher N fertigations, those in media had greatest N leachate loss when fertigated at 200 mg·L-1 of N. For balanced mesquite seedling growth and minimum N leaching losses, concentrations between 50 to 100 mg·L-1 of N are recommended. Implications of using a sand culture system vs. soilless growing substrate for nutrition studies will be discussed.

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Effect of aluminum on the growth and nutrition of tulip-poplar seedlings

Canadian Journal of Forest Research ◽

10.1139/x99-172 ◽

1999 ◽

Vol 29 (12) ◽

pp. 2003-2007 ◽

Cited By ~ 9

Author(s):

Heidi B Lux ◽

Jonathan R Cumming

Keyword(s):

Atmospheric Deposition ◽

Root Biomass ◽

Acidic Deposition ◽

Sand Culture ◽

Shoot Biomass ◽

Mature Trees ◽

Growth And Nutrition ◽

Low Threshold ◽

Tulip Poplar ◽

Poplar Seedlings

Atmospheric deposition of nitrogen and sulfate is acidifying some ecosystems, potentially increasing the availability of aluminum in the soil solution. The effects of Al on tulip-poplar (Liriodendron tulipifera L.) were investigated with seedlings grown in sand culture. Seedlings were exposed to Al at four concentrations ranging from 0 to 800 µM. Reductions of 77% in shoot biomass and 71% in root biomass were observed at 200 µM Al. Aluminum reduced the concentrations of multivalent cations in leaves and roots. The Ca concentration of leaves was reduced at 400 µM Al, and the Mg concentration of roots was significantly reduced at 200 µM Al. Relationships between tissue Ca, Mg, and Al indicated that Al alters the translocation of Ca and Mg to the shoots and the accumulation of Mg in the roots. If mature trees respond in a similar fashion as seedlings noted here, then tulip-poplar has a low threshold for A1 toxicity, which may lead to declines in the health of tulip-poplar populations in ecosystems exposed to elevated levels of acidic deposition.

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Effects of Sediments Phosphorus Inactivation on the Life Strategies of Myriophyllum spicatum: Implications for Lake Restoration

Water ◽

10.3390/w13152112 ◽

2021 ◽

Vol 13 (15) ◽

pp. 2112

Author(s):

Zhenmei Lin ◽

Chen Zhong ◽

Guolong Yu ◽

Yishu Fu ◽

Baohua Guan ◽

...

Keyword(s):

Shallow Lakes ◽

Root Biomass ◽

Submerged Macrophytes ◽

Myriophyllum Spicatum ◽

Morphological Characteristics ◽

Shoot Biomass ◽

Lake Ecosystem ◽

Total Biomass ◽

Life Strategies ◽

Eutrophic Lakes

Eutrophication often results in the loss of submerged vegetation in shallow lakes and turns the lake to be a turbid state. Recovery of submerged macrophytes is the key in the restoration of shallow eutrophic lakes to create a clear water state. However, internal loading control was considered as the critical process for the recovery of submerged macrophytes in shallow lakes after the external nutrient reduction. Phoslock® (Lanthanum modified bentonite) is a useful passivation material in controlling the internal loadings (release of phosphorus from the sediments), which was applied to restore the eutrophic lakes. However, the effects of Phoslock® on the growth and life strategies of submerged macrophytes are less focused so far. In the present study, we studied the responses in the growth and morphological characteristics of Myriophyllum spicatum to the addition of Phoslock® to the sediments. Our results showed that the addition of Phoslock® significantly decreased the contents of bioavailable forms of phosphorus in the sediments, such as redox-sensitive phosphorus bound to Fe and Mn compounds (BD–P), phosphorus bound to aluminum (Al–P) and organic phosphorus (Org–P). However, the concentration of the non-bioavailable forms of phosphorus in the sediments, such as calcium bound phosphorus (Ca–P), increased significantly in the Phoslock® treatments compared with the controls. At the end of the experiments, the total biomass, aboveground biomass and relative growth rate (RGR) of M. spicatum decreased significantly in the Phoslock® mesocosms compared with the controls. In contrast, the wet root biomass, root–shoot biomass ratio, root numbers and root length of M. spicatum were significantly higher in the Phoslock® treatments than that in the controls. Our results indicated that the growth of M. spicatum was suppressed by the addition of Phoslock®, and thus the biomass was decreased; however, the increase of root biomass might be beneficial to the inhibition of phosphorus release and resuspension of sediments and to the restoration of the lake ecosystem.

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Nitrogen Form and Concentration Affect Nitrogen Leaching and Seedling Growth of Prosopis velutina

HortScience ◽

10.21273/hortsci.41.1.239 ◽

2006 ◽

Vol 41 (1) ◽

pp. 239-243 ◽

Cited By ~ 3

Author(s):

Kathryn S. Hahne ◽

Ursula K. Schuch

Keyword(s):

Plant Morphology ◽

Biomass Accumulation ◽

Sand Culture ◽

N Leaching ◽

Nitrogen Form ◽

Prosopis Velutina ◽

Nitrate N ◽

Photosynthate Allocation ◽

N Rates ◽

Growth Of Seedlings

Velvet mesquite [Prosopis velutina Woot., Syn.: P. juliflora (Swartz) DC. var. velutina (Woot.) Sarg.] has become more popular in arid landscapes of the southwestern U.S., but little information on N requirements during the seedling stage is available. In addition to optimize growth of seedlings, minimizing N in runoff during production is an important consideration. Experiments were conducted to determine how biomass production and N leaching were affected first by different ratios of ammonium and nitrate N in sand culture and second by different N concentrations when seedlings were grown in two substrates. Mesquite seedlings produced the greatest biomass after 120 days when fertigated with a solution of 33 NO3–: 67 NH4+. Loss of N through leachate was 40% greater when NH + 4 comprised two thirds or more compared to one third or none in the fertigation solution. Nitrogen in leachate was highest after 16 weeks of treatment, coinciding with the reduced growth rate of seedlings. The second experiment utilized either sand or commercial growing media and a fertigation solution of 33 NO3–: 67 NH4+. Fertigation with 200 mg·L–1 N after 60 days in either substrate produced greatest biomass, while rates of 25, 50, or 100 mg·L–1 N produced about half of that biomass. With few exceptions, less N in either form was found in leachate when seedlings were grown in media and were fertigated with the two higher N rates compared to seedlings grown in sand at the two higher N rates. Plant morphology, biomass accumulation, photosynthate allocation, and the fate of N in the growing substrate and in leachate were strongly affected by the choice of growing substrate.

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Winter wheat roots grow twice as deep as spring wheat roots, is this important for N uptake and N leaching losses?

Plant and Soil ◽

10.1007/s11104-009-9898-z ◽

2009 ◽

Vol 322 (1-2) ◽

pp. 101-114 ◽

Cited By ~ 121

Author(s):

Kristian Thorup-Kristensen ◽

Montserrat Salmerón Cortasa ◽

Ralf Loges

Keyword(s):

Winter Wheat ◽

Spring Wheat ◽

N Uptake ◽

N Leaching ◽

Wheat Roots ◽

Leaching Losses

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Shrubland biomass and root-shoot allocation along a climate gradient in China

Plant Ecology and Evolution ◽

10.5091/plecevo.2021.1570 ◽

2021 ◽

Vol 154 (1) ◽

pp. 5-14

Author(s):

Jiangchao Guo ◽

Yaoxin Guo ◽

Yongfu Chai ◽

Xiao Liu ◽

Ming Yue

Keyword(s):

Biomass Allocation ◽

Root Biomass ◽

Community Level ◽

Shoot Biomass ◽

Total Biomass ◽

Scaling Exponent ◽

Climate Factors ◽

Allometric Relationships ◽

Climate Gradient ◽

Shrub Community

Background – Shrublands are receiving increasing attention because of climate change. However, knowledge about biomass allocation of shrublands at the community level and how this is regulated by climate is of limited availability but critical for accurately estimating carbon stocks and predicting global carbon cycles. Methods – We sampled 50 typical shrublands along a climate gradient in China and investigated the biomass allocation of shrubland at the community level and the effect of climate on biomass allocation. Shrub biomass was estimated using species-specific allometric relationships and the biomass of understory herbs was collected by excavating the whole plant. Regression analysis was used to examine the relationships between the biomass and the climate factors. RMA were conducted to establish the allometric relationships between the root and the shoot biomass at the community level.Key results – Shoot, root, and total biomass of shrub communities across different sites were estimated with median values of 206.5, 145.8, and 344.5 g/m2, respectively. Shoot, root, and total biomass of herb communities were estimated at 68.2, 58.9, and 117.2 g/m2, respectively. The median value of the R/S ratio of shrub communities was 0.58 and that of herb communities was 0.84. The R/S ratio of the shrub community showed a negative relationship with mean annual temperature and mean annual precipitation and a positive relationship with total annual sunshine and the aridity index. The R/S ratio of the herb community however showed a weak relationship with climate factors. Shoot biomass of the shrub community was nearly proportional to root biomass with a scaling exponent of 1.17, whereas shoot biomass of the herb community was disproportional to root biomass with a scaling exponent of 2.1.Conclusions – In shrublands, root biomass was more affected than shoot biomass by climate factors and this is related to water availability as a result of biomass allocation change of the shrub community. The understory herb community was less affected by climate due to the modification of the overstory–understory interaction to the climate-induced biomass allocation pattern. Shoot biomass of shrubs scales isometrically with root biomass at the community level, which supports the isometric theory of above-ground and below-ground biomass partitioning.

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Hydrophilic Gel Amendments to Sand Soil Can Increase Growth and Nitrogen Uptake Efficiency of Citrus Seedlings

HortScience ◽

10.21273/hortsci.39.2.267 ◽

2004 ◽

Vol 39 (2) ◽

pp. 267-271 ◽

Cited By ~ 10

Author(s):

J.P. Syvertsen ◽

J.M. Dunlop

Keyword(s):

Water Use ◽

Seedling Growth ◽

N Uptake ◽

Poncirus Trifoliata ◽

N Leaching ◽

Sand Soil ◽

N Losses ◽

Total N ◽

Uptake Efficiency ◽

N Uptake Efficiency

We tested the hypothesis that amendments of two hydrophilic gels to a sand soil would reduce N leaching losses and increase growth of citrus seedlings. Three-month-old seedlings of `Swingle' citrumelo [Citrus paradisi Macf. × Poncirus trifoliata (L.) Raf.] were transplanted into containers of steam-sterilized Candler sand, amended with a linear acrylamide/acrylate copolymer (PAM), and/or a cross-linked copolymer agronomic gel (AGRO). Two rates of each amendment were applied either alone or together and were either mixed into dry sand prior to seedling transplant, used as a root-dip slurry at transplant or applied to the soil surface in a solution after transplant. Seedlings were grown in the greenhouse for 5 months and irrigated to container capacity with a dilute nutrient solution without leaching. Pots were leached every 2 weeks and total N losses from the soil were measured in the leachate. PAM amendments increased N retention in soil slightly but PAM had no effect on plant growth, water use, N uptake, or N leaching relative to unamended control plants. The AGRO amendments increased seedling growth, plant water use and uptake of N from 11% to 45% above that of the unamended control plants depending on application method. AGRO decreased N concentrations in the leachate to as low as 1 to 6 mg·L-1. Only 6% of the total applied N was leached from the AGRO treatments, which was about half that from the untreated control plants. There was no additional benefit of using both amendments together or of an additional AGRO root dip treatment. The largest plants used the most water, required the most N and had the greatest N uptake efficiency. AGRO amendments clearly enhanced seedling growth, increased their N uptake efficiency, and reduced N losses from this sand soil.

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Assessments of N leaching losses from six case study dairy farms using contrasting approaches to cow wintering

Proceedings of the New Zealand Grassland Association ◽

10.33584/jnzg.2012.74.2874 ◽

2012 ◽

pp. 51-55 ◽

Cited By ~ 3

Author(s):

J.M. Chrystal ◽

R.M.Monaghan D. Dalley ◽

T. Styles

Keyword(s):

Dairy Cow ◽

N Uptake ◽

Dairy Herd ◽

High Potential ◽

System Level ◽

N Leaching ◽

Forage Crops ◽

N Losses ◽

Total N ◽

Leaching Losses

The expansion of the southern dairy herd in New Zealand has raised a number of concerns about the sustainability of grazing brassica forage crops. Here we provide an assessment of the contribution of these crops to the potential for N losses to water at a wholefarm system level, and compare these with metrics derived for systems that use alternative approaches for wintering cows. The risks of nutrient losses to water from six Monitor Farms that use contrasting approaches to dairy cow wintering were assessed using the Overseer® Nutrient budgets model (Overseer). This modelling assessment was supplemented with detailed information about the management of effluent generated from off-paddock cow wintering facilities such as wintering pads and covered housing. Predictions of N losses from individual farm blocks indicated that both winter- and summer-grazed brassica forage crops have a relatively high potential for N leaching losses. Expressed at a whole-system level (i.e. accounting for the milking platform, winter forage crop and other support land), the winter forage crops accounted for between 11 and 24% of total N leaching losses, despite representing only 4 to 9% of the area. The high N leaching losses predicted for summer-grazed forage crops were attributed to the limited opportunity for N uptake of excreted urinary N by the following new pasture. Another risk identified for some farms was the current practice of applying effluents collected from off-paddock facilities to land during winter. These assessments suggest that off-paddock cow wintering systems can help to minimise N losses from farms to water, although the storage and safe return to land of effluents and manures generated from the housing facilities is essential if this potential benefit is to be realised. Our assessments also suggest that summer crop paddocks have a relatively high potential for N leaching losses, although further research is needed to confirm this. Keywords: dairy cow wintering, Southland, nitrate leaching, grazed brassica forage crops.

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Opportunities for Increased Nitrogen Use Efficiency in Wheat for Forage Use

Plants ◽

10.3390/plants9121738 ◽

2020 ◽

Vol 9 (12) ◽

pp. 1738

Author(s):

Nirmal Sharma ◽

Raquel Schneider-Canny ◽

Konstantin Chekhovskiy ◽

Soonil Kwon ◽

Malay C. Saha

Keyword(s):

Nitrogen Use Efficiency ◽

Crude Protein ◽

Nitrogen Nutrition ◽

N Uptake ◽

N Fertilization ◽

Shoot Biomass ◽

Total Biomass ◽

Strong Positive Correlation ◽

Nitrogen Use ◽

Use Efficiency

Wheat is a major cool-season forage crop in the southern United States. The objective of this study is to understand the effect of nitrogen (N) fertilization on wheat biomass yield, quality, nitrogen use efficiency (NUE), and nitrogen nutrition index (NNI). The experiments were conducted in a greenhouse and a hoop house in a split-plot design, with three replications. Twenty wheat cultivars/lines were evaluated at four N rates (0, 75, 150, and 300 mg N.kg−1 soil) in the greenhouse and (0, 50, 100, and 200 mg N.kg−1 soil) in the hoop house. In general, high-NUE lines had lower crude protein content than the low-NUE lines. None of the cultivars/lines reached a plateau for biomass production or crude protein at the highest N rate. The line × N rate interaction for NUE was not significant in the greenhouse (p = 0.854) but was highly significant in the hoop house (p < 0.001). NNI had a negative correlation with NUE and biomass. NUE had strong positive correlations with shoot biomass and total biomass but low to moderate correlations with root biomass. NUE also had a strong positive correlation with N uptake efficiency. Lines with high NUE can be used in breeding programs to enhance NUE in wheat for forage use.

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NLEAP Computer Model and Multiple Linear Regression Prediction of Nitrate Leaching in Vegetable Systems

HortTechnology ◽

10.21273/horttech.12.2.250 ◽

2002 ◽

Vol 12 (2) ◽

pp. 250-256 ◽

Cited By ~ 2

Author(s):

Hudson Minshew ◽

John Selker ◽

Delbert Hemphill ◽

Richard P. Dick

Keyword(s):

Linear Regression ◽

Multiple Linear Regression ◽

Nitrate Leaching ◽

Cover Crops ◽

N Uptake ◽

N Leaching ◽

Residual Soil ◽

Vegetable Crops ◽

Crop N Uptake ◽

Mlr Model

Predicting leaching of residual soil nitrate-nitrogen (NO3-N) in wet climates is important for reducing risks of groundwater contamination and conserving soil N. The goal of this research was to determine the potential to use easily measurable or readily available soilclimatic-plant data that could be put into simple computer models and used to predict NO3 leaching under various management systems. Two computer programs were compared for their potential to predict monthly NO3-N leaching losses in western Oregon vegetable systems with or without cover crops. The models were a statistical multiple linear regression (MLR) model and the commercially available Nitrate Leaching and Economical Analysis Package model (NLEAP 1.13). The best MLR model found using stepwise regression to predict annual leachate NO3-N had four independent variables (log transformed fall soil NO3-N, leachate volume, summer crop N uptake, and N fertilizer rate) (P < 0.001, R2 = 0.57). Comparisons were made between NLEAP and field data for mass of NO3-N leached between the months of September and May from 1992 to 1997. Predictions with NLEAP showed greater correlation to observed data during high-rainfall years compared to dry or averagerainfall years. The model was found to be sensitive to yield estimates, but vegetation management choices were limiting for vegetable crops and for systems that included a cover crop.

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Growth Responses of Boreal Scots Pine, Norway Spruce and Silver Birch Seedlings to Simulated Climate Warming over Three Growing Seasons in a Controlled Field Experiment

Forests ◽

10.3390/f11090943 ◽

2020 ◽

Vol 11 (9) ◽

pp. 943

Author(s):

Katri Nissinen ◽

Virpi Virjamo ◽

Antti Kilpeläinen ◽

Veli-Pekka Ikonen ◽

Laura Pikkarainen ◽

...

Keyword(s):

Norway Spruce ◽

Scots Pine ◽

Root Biomass ◽

Growing Season ◽

Silver Birch ◽

Shoot Biomass ◽

Growth Responses ◽

Growing Seasons ◽

Simulated Climate ◽

Shoot And Root Biomass

We studied the growth responses of boreal Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies L. Karst.) and silver birch (Betula pendula Roth) seedlings to simulated climate warming of an average of 1.3 °C over the growing season in a controlled field experiment in central Finland. We had six replicate plots for elevated and ambient temperature for each tree species. The warming treatment lasted for the conifers for three growing seasons and for the birch two growing seasons. We measured the height and diameter growth of all the seedlings weekly during the growing season. The shoot and root biomass and their ratios were measured annually in one-third of seedlings harvested from each plot in autumn. After two growing seasons, the height, diameter and shoot biomass were 45%, 19% and 41% larger in silver birch seedlings under the warming treatment, but the root biomass was clearly less affected. After three growing seasons, the height, diameter, shoot and root biomass were under a warming treatment 39, 47, 189 and 113% greater in Scots pine, but the root:shoot ratio 29% lower, respectively. The corresponding responses of Norway spruce to warming were clearly smaller (e.g., shoot biomass 46% higher under a warming treatment). As a comparison, the relative response of height growth in silver birch was after two growing seasons equal to that measured in Scots pine after three growing seasons. Based on our findings, especially silver birch seedlings, but also Scots pine seedlings benefitted from warming, which should be taken into account in forest regeneration in the future.

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